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UNITED STATES OF AMERICA., 

» 9—167 



Compliments of tbe Hutbor, 



The Work of the Lick Observatory 

1888-1897. 



EDWARD S. HOLDEN. 




Reprint from Popular Astronomy for August, 1897. 




ASTRONOMICAL WORK AT LICK OBSERVATORY. 



EDWARD S. HOLDEN.* 



For Popular Astronomy. 

In your letter of June 26 you ask for some account of the work 
in progress here for Popular Astronomy, which I am very glad 
to give. A report of the sort is annually made to the Regents of 
the University of California and from the forthcoming report the 
following summary is made. It must be remembered that the 
work of this year is in continuation of previous work, and often 
in pursuance of plans laid down in 1874 — 23 years ago. While 
the resources of the Lick Observatory are large in comparison 
with those of many College Observatories they are very small in 
relation to those of the great establishments of Greenwich, Paris, 
Pulkova, Washington and Harvard College. For instance the 
whole available income of the Lick Observatory for the coming 
fiscal year (exclusive of salaries) is $5,145. This sum must keep 
all the buildings painted and in repair; keep all our reservoirs 
and some five miles of underground pipes in order; provide for 
all painting, plumbing, brick-laying, pipe-fitting, carpenter work, 
machine work, etc. etc., in the Observatory and in the houses of 
astronomers and workmen; buy all supplies such as lumber, hay, 
iron, brick, etc.; pay for all instrument-making not done in the 
Observatory; pay all freight, express and telegraph bills; main- 
tain a telephone line 17 miles long in good order; pay for fuel; 
purchase books for the library ; provide an}' needed apparatus 
for all the instruments; and, this year, buy much of the material 
needed for an eclipse expedition to India. It is no small task to 
make the small income cover the requirements. Every want 
which is felt in a large city is felt here. The circumstances at 
Mount Hamilton are as different as possible from those at East- 
ern Observatories. There each person must provide for his own 
personal comfort; here the comfort of each one must be secured 
by the expenditure of the annual appropriation. If it is insuf- 
ficient ever> person suffers in some degree. 

* Director of Lick Observatory. 



Astronomical Work at hick Observatory. 



The astronomical efficiency of the Lick Observatory cannot be 
properly estimated without taking such material and social con- 
siderations into account Under the circumstances I do not 
think it is too much to claim that its efficiency during the nine 
years of its life has been satisfactory. This has only been at- 
tained by good will and earnest effort on the part of all con- 
cerned — regents, astronomers, mechanics, workmen. The sum- 
mary of work for which you asked, is given below. 

Double Stars have been measured here in past years in great 
numbers by Professor Burnham, and at the present time Profes- 
sors Schaeberle, Hnssey and Aitken are engaged in such work for 
parts of their time. 

The Satellites of Mars, Jupiter, Uranus and Neptune have been 
regularly observed here for the past nine years by Messrs. Schae- 
berle, Barnard, Campbell and Hussey. A fifth satellite of Jupiter 
was discovered by Professor Barnard in 1892. 

The Planets, especially Mars, Jupiter, Saturn (and also Venus 
and Uranus) have been systematically observed for their physical 
features at every opposition by Messrs. Holden, Schaeberle, Keel- 
er, Barnard and Hussey. For several oppositions of Mars the 
planet has been followed by Messrs. Holden, Schaeberle and 
Campbell during every available hour. 

Comets have been discovered here in great numbers. Ten com- 
ets (seven unexpected) were discovered by Professor Barnard 
from 1888 to 1892; five (four unexpected) by Mr. Perrine from 
1895 to date. The long series of observations of these and other 
comets by Messrs. Barnard, Campbell, Hussey, Perrine and Ait- 
ken are a contribution to science even more important than the 
discoveries themselves. 

Comet- Orbits have been computed hereby Messrs. Schaeberle, 
Campbell, Hussey, Perrine and Aitken; and all comets discovered 
at the Observatory have had their first orbits calculated by of- 
ficers of the University. In this work Professor Leuschner, of 
Berkeley, a former student here, and his assistant, Mr. F. H. 
Seares, have rendered assistance which is much appreciated. 

Meteors have been observed and photographed here (and else- 
where) by all the astronomers, and their orbits calculated by 
Messrs. Holden and Schaeberle. 

Double-Star Orbits have also been computed by Professor 
Schaeberle. 

The Zodiacal Light was regulaidy observed (visually) by Pro- 
fessor Barnard. 

The Aurora has been regularly observed (spectroscopically) by 
Professor Campbell. 



Edward S. Hoi den. 



Typical or remarkable Cloud-forms are regularly photographed 
by Mr. Pauli, janitor of the Observatory. 

Nebulas have been observed (visually, photographically and 
spectroscopically) by Messrs. Holden, Burnham, Schaeberle, 
Barnard and Campbell. 

Star maps have been made and published by Mr. Tucker. 

Photometry : (photographic and visual) — of eclipses and of 
stars — has been attended to by Messrs. Holden, Schaeberle, 
Campbell and Leuschner. 

Solar Eclipses: those of January and December 1889, April 
1893, August 18'.-6, have been observed by Messrs. Burnham, 
Schaeberle, Keeler, Barnard, Hill, Leuschner and Campbell — and 
the latter will observe the eclipse of January 1898 in India. 

Lunar Eclipses. — All lunar eclipses visible here have bren ob- 
served. 

OccuJtations. — A series of occulta tions has been observed here 
by Professor Leuschner. 

Transits of Mercury. — Three transits of Mercury have been ob- 
served (either visually or photographically). 

Transit ol Venus — That of 1882 was successfully photographed 
here by Professor Todd. 

Catalogues of Stars. — Two such are in progress of prepara- 
tion. 

1st. A catalogue of double-stars and of Coast Survey stars 
from observations by Professor Schaeberle has been (partly) re- 
duced, on lines laid down by myself, by Messrs. Schaeberle, Camp- 
bell, Leuschner, Aitken and Professor Bigelow and Mrs. Upde- 
graff. Profe-sor Aitken has spent more than a year on this 
work. 

2d. A catalogue of 38,000 stars from Washington observa- 
tions is well towards completion. The reductions have been 
made chiefly by Messrs. Holden and Aitken. The original obser- 
vations as printed were full of errors. The final places will be 
considerably more precise in declination and somewhat less pre- 
cise in right ascension than the southern zones of Argelander. 

Solar Photography. — Some 1,800 negatives of the Sun (taken 
with the photoheliograph) have been secured by Mr. Perrine and 
since April, 1896, some 450 more by Mr. Colton. Excellent ex- 
perimental solar photographs on a large scale have been made 
with the 36-inch telescope and it is hoped to go very much further 
with this work during the summer of 1897. 

Lunar Photography. — A very full series of focal negatives has 
been made with the 36-inch telescope chiefly by Messrs. Holden 



Astronomical Work at Lick Observatory. 



and Colton. An atlas on the scale of X-feet to the Moon's di- 
ameter has been prepared from these by Professor Weinek at 
Prague. Enlargements in the telescope have been made by 
Messrs. Holden, Colton and Perrine and 5 plates of a Moon at- 
las on the scale of Ill-feet to the Moon's diameter have already 
been distributed. Twelve more plates are now in the hands of 
the engraver and will soon be issued ; and about 20 more are 
ready to be published when the funds are available. The atlas 
will be complete with about 60 plates. All the work in the dark 
room is done by Mr. Colton. 

Photographs of the Milky Way. — A great number of such pic- 
tures has been obtained by Professor Barnard who is preparing 
them for publication. 

Photographs of tlanets (especially of Jupiter) have been regu- 
larly made by Messrs. Holden, Schaeberle and Colton. 

Photographs of Comets have been secured by Messrs. Barnard, 
Hussey and Colton. 

Visual Photometry. — Two fine photometers of Professor Pick- 
ering's design have lately been given to us by Miss Bruce. They 
will be used by Professor Aitken, chiefly on double-stars at pres- 
ent. 

Spectroscopic observations of nebulae, new stars, comets, stars 
and planets, have been made by Messrs. Keeler and Campbell. 
The chief problem of the great telescope is to determine the mo- 
tion of the solar system by spectroscopic observations. It was 
first attacked here in 1888 and since that time it has been con- 
sidered as our most important work. The results now attained 
by Professor Campbell are of unexampled precision, and some of 
them will be published shortly. Man}' unexpected delays have 
occurred in this research which has been under the charge of 
Messrs. Keeler, Crew and Campbell. 

Time-signals are sent out daily. Mr. Tucker is in charge of our 
clocks. 

Meridian-Circle Observations. — Mr. Tucker has completed a 
fine series of observations of all stars contained in any of the 
great Ephemerides and not contained in the Berliner Jahrbuch. 
This work is all ready to print. He has also determined the 
places of a long list of stars used by Professor Doolittle to deter- 
mine the latitude of Lehigh University. The division errors of 
the 1° spaces of both circles of the instrument have been deter- 
mined by Mr. Tucker with the assistance of Mr. Aitken. 

Meteorological Observations (tri-daily) have been regularly 
made. They are now in charge of Professor Aitken. A summan' 



Edward S. Holden. 



of all meteorological observations made here from 1888 to 1897 
is in course of preparation by Mr. Perrine. 

Earthquake Observations are obtained on our two Seismo- 
graphs which are in charge of Mr. Perrine. A complete list of 
all recorded earthquakes on the Pacific Coast from 1769 to 
1897 has just been prepared by Professor Holden. 

Publications of the Observatory. The Observatory has al- 
ready issued three quarto volumes and five octavos beside several 
pamphlets and the Moon-Atlas. The Smithsonian Institution 
has lately published an octavo prepared here by Professor 
Holden — Mountain Observatories — and will probably print his 
list of recorded earthquakes, just mentioned. Notices from the 
Lick Observator3' regularly appear in the publications of the As- 
tronomical Society of the Pacific. More than 1200 contribu- 
tions to astronomical and other journals have been made by the 
officers of the Observatory since 1888. 

Trial of the Crossley Reflector. — This fine instrument, which 
had done such good work in the hands of Mr. Common, was 
presented to the Lick Observatory by Mr. Crossley in 1895. It 
was completely mounted in June, 1896, and given over to Profes- 
sor Hussey for trial. The work begun in 1896 is now being 
prosecuted. Photography in the Newtonian and principal foci 
will be tried by Professor Hussey, and Professor Campbell has a 
programme of spectroscopic observations to be carried on with 
the Bruce spectrograph (constructed here) in the principal focus. 
A powerful driving-clock (the Bruce clock) has been made here 
from drawings by Professor Hussey. It is essentially a copy, in 
little, of the Warner & Swasey clock of the 36-inch equatorial. 
Its conical pendulum weighs about 56 pounds. 

The Schaeberle 18-inch Reflector has been used for some years 
past in experiments in celestial photography by its maker, Pro- 
fessor Schaeberle. Very interesting photographs of Jupiter have 
been obtained. 

The Crocker Photographic Telescopes (a pair of Willard por- 
trait lenses) will soon be mounted in a new Dome near the Cross- 
ley Reflector. A 12-inch mirror (by Professor Schaeberle) of ver} r 
short focus is to be mounted on the same stand. 

Lick Observatory, July 7, 1897. 



